Is this windows 2008 a cluster paired? If answer is yes, then you would need to wait for a new BA Client after 6.2.2.
It seems that in windows 2008, systemstate backup will backup all files that are present as a service in services.msc irregardless of state. Meaning to say, if you have a service and its path is pointed to a shared cluster disk, systemstate backup will attempt to back that file up. That also explain why systemstate backup now is in GB not in MB comparing with windows 2003.
To work around using windows backup feature, you need to apply this hotfix and do exclusion to these files however you would need to perform a file level backup for these files since they are excluded from Systemstate backup.
http://support.microsoft.com/default.aspx?scid=kb;EN-US;980794
As for TSM BA Client, I have raised this to support and they have escalate this to client development team on how can they get this working as TSM will pull all the list from systemstate just like windows backup feature however this hotfix does not apply to TSM and in such, TSM development will need to come out if a new build.
If you encounter any of these errors during systemstate backup, Microsoft have this KB that its TSM issue and nothing to do with MS.
http://support.microsoft.com/kb/2011841
With this, you will not be able to raise any support from MS.